On fixed-bed gas generation

Personal opinion: It’s like living at home; those with wealthy families can improve their standard of living, while those with average financial means still have to get by. If a company is strong and well-funded, it can go straight for advanced pressurized gasification technology, which offers leading-edge performance and meets environmental standards. Conversely, if there are financial issues, the fixed-bed batch gasification process can be adopted; upgrades to pressure gasification can be carried out later once it becomes profitable. Although fixed-bed batch gasifiers have certain drawbacks, the investment required for their unit production capacity is only one-third of that for pressure gasification, resulting in a significant advantage in terms of financial costs. Of course, the gasification process is the key to this project; it is recommended that the original poster conduct more extensive evaluations and discussions in order to finally determine the technology to be used. Personal analysis should adhere to the following principles: 1. Sufficiently advanced, yet reliable and secure ； 2. Suitable for the actual conditions of enterprises ； 3. Full consideration must be given to the factors related to raw material availability ； 4. Plan in one step, implement in phases. This post was last edited by zjyang168168 on 2007-12-17 08:28.]

Fixed-bed reactors are bound to be phased out; they not only consume a lot of energy but also require high-quality coal, resulting in high costs. Currently, chemical companies receive certain subsidies, such as discounted electricity rates and preferential transportation costs, but these subsidies are set to be abolished soon. It’s already good enough if we don’t suffer losses once it’s built; we’re even aiming to make a profit. My factory has been in operation for 30 years – it’s not large-scale, but it does have a decent size. Currently we still use fixed-bed reactors, but we need to change that; otherwise we’ll face closure. From an energy-saving perspective, fixed-bed reactors must be phased out. **Small and medium-sized enterprises with high energy consumption will also be gradually shut down, so I recommend avoiding the use of fixed-bed reactors. There are methanol plants everywhere these days; if your technology is not as good as theirs, how can you compete with them?

Regarding the choice of gasification process, it depends on the local conditions. If there is bituminous coal available in your area, that makes sense; but if the coal available is high-sulfur coal, bituminous coal, or lignite, then coal slurry or pulverized coal gasification is the more appropriate option. Of course, the fixed-bed gas generation technology is outdated, operates in harsh conditions, and is considered a technology that should be phased out; in Shandong, its use is currently restricted. It means spending less money.

Thank you all for your suggestions. However, I have no control over the choice of manufacturing process; at present, the raw coal needed has not been secured yet, and the approval process is still pending. It is estimated that another 3 years will be required for construction once the approval is granted. The design institute believes that a fixed-bed system can be built in a shorter time frame, with results becoming visible soon. It’s frustrating!

Especially with intermittent water gas generators, the coal used is very selective – it has to be of high quality, and the options are quite limited

Fixed-bed technology is too outdated, causes severe pollution, has a low fuel utilization rate, and leads to significant environmental damage. However, this technology is already well-developed; the equipment can generally be produced domestically, the investment required is relatively low, and the construction period is short. It does require a large amount of water. The technology using Texaco’s methods is quite mature in terms of operation, but the investment is higher than that for fixed-bed technology, and the construction period is also longer. From a long-term perspective, it would be best to use Texaco’s water-coal slurry fluidized-bed technology

TEXACO is not just a little more expensive than fixed-bed systems – it’s much more costly. I suggest considering domestic gasification technologies; there aren’t many available, so you can look for some information on forums to compare them

I agree with the view from the second floor: fixed-bed gas generation indeed requires a single type of coal (high-quality anthracite), and as the price of anthracite keeps rising, cost considerations must be taken into account. For the pressurized gasification of water-coal slurry, the type of coal required is also relatively limited; Shell and Endel boilers can be considered, but the initial investment is very high.

I agree with the point made on the 2nd floor. I am a worker at a fertilizer company in Shandong Province; most of the enterprises there, including those with new projects, use fixed-bed reactors. From a technical perspective, new coal gasification technologies are feasible; however, to be used in industrial production and generate economic value for enterprises, merely having advanced technology is not sufficient. Cutting-edge technologies may represent the trend for the future, but they are not necessarily the practical choice for enterprises. More in-depth research is also necessary in terms of operation, maintenance, and production costs. The advancement and maturity of technology, the availability of raw materials, the operability of production, operating costs, the investment and duration of the construction period, and the maintainability of the facility. These are all factors that must be taken into account in industrial production. The fixed-bed batch gasification process has been in use for over 100 years; it features mature technology and low investment costs, which is why it is the gasification technique adopted by most fertilizer manufacturers in our province. China’s first atmospheric pressure fixed-bed intermittent air gasifier was designed in 1882; after 1913, it was improved and developed into the current UGI furnace. China’s first UGI gas stove was the Φ2745 model, which was introduced from the United States by Nanjing Yonglining in 1935. In 1960, after the founding of the country, Taihua introduced a Φ3600 gas furnace from the Soviet Union. Over the years, technical experts in the fertilizer industry have continuously worked to innovate this process, with many new technologies being adopted. As a result of nearly a century of development, this traditional process is now very different from what it used to be; significant improvements have been made in terms of energy consumption, the amount of gas produced per furnace, and operational efficiency. The new technologies currently used in fixed-bed batch gasification include furnace diameter expansion, the use of conical water jackets in place of traditional straight jackets, replacing single-furnace heat recovery with a combined waste boiler shared by multiple furnaces, combined gas scrubbing towers, combined steam drums with automatic level control, automatic coal feeding technology, automatic hydrogen ratio adjustment technology, automatic furnace condition optimization technology, an external furnace bottom, ash removal without shutting down the furnace, and large-scale Φ8500 air blower heat recovery systems. For ordinary fertilizer companies, the cost of replacing free air with expensive pure oxygen as a means to replace Shanxi white coal with local bituminous coal is unaffordable. Due to constraints such as investment, domestic production of equipment, and subsequent process equipment, advanced gasification technologies cannot be adopted in the short term. For these enterprises, it is necessary to rely on independent innovation, utilize new technologies to improve the existing fixed-bed gasification process, and at the same time apply briquette technology to reprocess the coal dust generated during the processing of lump coal entering the plant, so as to reduce energy consumption. For large-scale new ammonia synthesis systems, especially new methanol production plants, it is recommended to use pure oxygen pressurized continuous gasification with a high processing capacity.

It’s true that fixed-bed technology is outdated, and there’s nothing wrong with that! As the saying goes, \"where there is a need, there is a solution.\" If your organization intends to use coal sources and of such quality that it enables local utilization, then a small investment might be worth considering! Compared to the investment required for fixed-bed systems, Texaco’s approach is not even comparable. My personal advice is that it’s important to act according to one’s capabilities; as long as production is managed properly and all the necessary conditions are met, fixed-bed systems can still be profitable. Large investments do not necessarily yield large returns! Just joking – when you can’t afford a color TV, it’s better to buy a black-and-white one first; you can still enjoy watching TV dramas in their original format! Second suggestion: All preliminary research needs to be thorough, and it is necessary to predict the supply of raw materials as well as the conditions in the surrounding market over the next 10 years or so. In fixed-bed systems, the raw material coal type is the most vulnerable aspect, so a long-term perspective is essential! This post was last edited by GSP on 2007-12-21 12:52 ]

Fixed-bed reactors can’t be used anymore, right? **It won’t be approved, right? A gray fused-bed fluidized bed can be used; it requires little investment yet delivers good results

Fixed-bed systems not only consume a lot of energy, but they also require high-quality coal for operation, resulting in high costs. Currently, chemical companies receive certain subsidies, such as reduced electricity costs and transportation discounts; however, these subsidies are set to be eliminated soon. Fixed-bed gas generation is stable and requires less investment, but it fails to meet environmental standards. Pressurized coal gasification requires large investment, the technology is fairly successful, but it also involves high risks.

Domestic gray pyrolysis gasification technology has gradually matured; it requires less investment and yields quick results!

Fixed-bed gas generation is stable, requires less investment, but fails to meet environmental standards. Pressurized coal gasification requires large investment, but the technology is fairly successful. However, the financial capabilities of the enterprise must be taken into consideration; in terms of maintenance costs, pressurized gasification is much more expensive. It is still possible to use smaller furnace models capable of operating at 2600 degrees, and these can also burn small-sized coal particles

I agree with your view. Methanol producers are currently enjoying good profits, but these profits stem from the rapid increase in demand for methanol, resulting in a supply shortage. In two to three years, once many more methanol production facilities come online, competition will focus on costs; it will be difficult to compete in the market if management is poor or the production processes are not efficient.

Everyone has their own opinion. I’ve also read about coal gasification processes; in theory, it’s best to choose the method that suits one’s own needs……

There are quite a few types of fluidized-bed gasification furnaces available in China these days; the ash fusion furnace and the Ende furnace are both good options. I’ve only heard of the ash fusion furnace – I haven’t used it myself – but I’ve worked with the Ende furnace for some time and find it to be quite satisfactory. If one is looking to scale up production, this furnace could be a good choice. Those who need information on the Ende furnace can get in touch.