【HaiChuan Discussion】Which petrochemical plants have undergone low-temperature waste heat recovery upgrades, and what are the results?

The low-temperature waste heat recovery system at Zhongyuan Petrochemical has been put into use. Authors: Zhou Jianhong, Zhang Liang. Source: China Chemical Industry News, April 17, 2020. According to China Chemical New Network, the low-temperature waste heat recovery system at Zhongyuan Petrochemical’s MTO plant was recently put into operation, delivering good energy-saving and environmental protection benefits; it is expected to generate an additional profit of 260,000 yuan per month. 　　Previously, the demand for low-pressure steam at Zhongyuan Petrochemical was 20–23 tons per hour; of this amount, 9–12 tons per hour was generated by cooling and depressurizing medium-pressure steam, which was far from sufficient to meet the production needs. The Olefins Department 2 of this company has carried out an in-depth \"100-Day Campaign for Efficiency Improvement\" initiative. In line with the goal of maximizing efficiency and adhering to the principles of energy conservation and environmental protection, it uses the low-temperature wastewater from the MTO unit, at temperatures between 90°C and 120°C, to generate low-pressure steam. 　　This project utilizes patented technology to install a set of temperature-raising absorption heat pump units. After the waste heat recovery system is put into use, it can produce 5 to 6 tons of low-pressure steam per hour, save 900 million kilowatt-hours of electricity, and reduce the energy consumption of the plant by 10 to 15 kilograms of standard oil per ton of diolefin.

What patented technologies are used in this project? Are they proprietary or imported? Which design institute was responsible for the design? ? @RedLee_ZZHI @ZhizheMing @654262293 @rjs999 @1573

What kind of unit is a temperature-raising absorption heat pump unit, and is it domestically produced?

The Jiujiang Petrochemical Low-Temperature Waste Heat Utilization Project has been approved through signing! (Attached: Low-temperature waste heat technology and strategies) 2018-06-20 07:00 On June 8, the Technology Department of Sinopec organized a technical evaluation meeting for the project aimed at developing power generation systems using organic working fluids derived from low-temperature waste heat in refineries, in Jiujiang. After on-site inspections and evaluations by experts from Sinopec’s Department of Science and Technology, Department of Energy Management and Environmental Protection, Chemicals Business Unit, Sinopec Energy Conservation Technology Service Company, Xinxing Petroleum Beijing Company, Wuhan Petrochemical and other organizations, it was unanimously agreed that the project aimed at making use of low-temperature waste heat in refineries; it developed a power generation technology using organic working fluids, created the necessary power generation equipment and supporting systems, and thus produced China’s first set of centrifugal turbine-based organic Rankine cycle power generation units, which met all the design requirements. The overall technology is internationally advanced. The development project for generating electricity using organic working fluids derived from low-temperature waste heat in refineries was initiated in 2015, with Jiujiang Petrochemical, Sinopec Luoyang Engineering Company, and the 711th Research Institute of CSSC jointly undertaking the development tasks. Utilizing the low-temperature hot water at around 95°C left over from Jiujiang’s 8 million tons per year oil product quality improvement project, this project developed a 1,600-kilowatt centrifugal turbine-based organic Rankine cycle power generation unit that uses isobutane as the organic working fluid. An industrial demonstration was carried out, filling a gap in China’s field of large-scale power generation using low-temperature waste heat from refineries. The power generation unit was put into operation on July 25, 2016, and successful grid connection for power generation was achieved. From August 3 to 6, the 72-hour assessment was successfully passed. Industrial applications have shown that the entire equipment operates smoothly and reliably, with stable system control, demonstrating good adaptability to varying loads.

On the low-temperature waste heat utilization technologies in petrochemical enterprises: During their production processes, petrochemical enterprises inevitably generate a large amount of waste heat. The low-temperature waste heat in refining enterprises refers to the heat generated during the production process that is higher than the storage temperature of the oil products or the temperature required by the process itself, and which is not recovered. It is generally believed that heat with a temperature range of 80–200°C can be recovered as low-temperature waste heat ； Heat above 200°C is mainly used to generate steam. The low-temperature waste heat that is not utilized during the production process is ultimately discharged into the environment in various forms as wasted thermal energy. It is mainly released through four pathways: discharge from air coolers, discharge from intermediate product tanks, discharge from flue gas systems, and discharge from circulating water cooling systems. Among them, the low-temperature waste heat discharged by the circulating water cooling system accounts for about 80% of the total low-temperature waste heat in the plant. Data shows that the low-temperature waste heat in refining and chemical processing enterprises is mainly generated in atmospheric and vacuum distillation, catalytic cracking, delayed coking, and hydrogenation units; the low-temperature waste heat from these four areas accounts for 60% to 80% of the total low-temperature waste heat in the entire plant. The main ways to recover and utilize low-temperature waste heat are as follows:

Jinxī Petrochemical, Hainan Refining & Chemical, and Hengli Petrochemical are all engaged in ultra-low pressure steam power generation, using saturated steam at a pressure of 0.06 Mpa as well as waste heat from hot water at 118°C for power production. It is difficult at the beginning, but it becomes easier once the process gets under way.

It seems that Sinopec Refining and Chemicals is also involved; I’ll check that later

What’s this company like? ================== Sinopec Energy Saving Technology Service Co., Ltd. was established in October 2011 on the basis of the Sinopec Energy Saving Technology Service Center. It is under the jurisdiction of Sinopec Consulting Company and is a wholly-owned subsidiary of Sinopec. In January 2012, it became one of the fourth batch of energy service companies approved by the National Development and Reform Commission and the Ministry of Finance. It is also a member of the Shanghai Energy Service Industry Association. The company mainly engages in contract energy management and the optimization of energy systems in petrochemical enterprises, offering professional services across various aspects such as energy assessment, auditing, diagnosis, optimization, and management. Building on the energy-saving projects carried out by Sinopec, Sinopec Energy Saving Technology Services Company strives to develop a comprehensive team based on its own diagnostic staff, with support from external experts. It provides professional services across various aspects such as energy assessment, auditing, design, construction, management, and maintenance, aiming to become a leader in the energy-saving services industry during the 12th Five-Year Plan period. Sinopec Energy Saving Technology Services Company is dedicated to the implementation and promotion of contract energy management within Sinopec. Sinopec was the first to successfully implement two contract energy management demonstration projects at Yanshan Petrochemical: stepless air volume control for compressors and waste steam recovery, achieving excellent energy-saving results. Since then, the company has successively carried out multiple contract energy management projects in the petrochemical industry, achieving an annual energy savings of 30,000 tons of standard coal. Sinopec Energy Saving Technology Services Company has currently provided energy-saving technology services to several petrochemical enterprises, such as the plant-wide energy optimization projects at Zhanjiang Dongxing Petrochemical and Puguang Natural Gas Purification Plant in the Zhongyuan Oilfield, helping these enterprises to realize an energy-saving potential of over 30,000 tons of standard coal per year ； The plant energy optimization projects carried out by Maoming Petrochemical and Shanghai Petrochemical have unlocked energy-saving potential in these enterprises amounting to over 100,000 tons of standard coal per year. Sinopec Energy Saving Technology Service Company actively carries out various research efforts related to energy conservation, emission reduction, and green low-carbon development: Sinopec’s energy saving plans for the 12th and 13th Five-Year Plans ； Sinopec’s 2030 Science and Technology Development Plan for Energy Conservation ； Carbon accounting, carbon inventory ； Formulation of relevant energy-saving standards ； Formulation of relevant greenhouse gas emission standards, etc. Sinopec Energy Saving Technology Service Company possesses energy-saving technologies such as overall energy system optimization, hydroprocessing of pyrolysis gasoline, recovery of waste heat from aromatics, energy-saving upgrades to circulating water systems, stepless control of gas flow, recovery of waste steam, and mechanical vacuum systems. In terms of greenhouse gas reduction, it focuses on conducting carbon inventory assessments, carbon calculations, developing carbon models, and formulating relevant standards for petrochemical enterprises.

In the design phase, the Zhongke project will take advantage of scale effects and integration benefits, implement comprehensive utilization of heat sources, and achieve deep thermal integration between various units. It will give full consideration to recovering low-grade heat energy throughout the plant, with waste heat recovery systems in place to utilize this low-temperature waste heat for cooling purposes. As a result, the project’s overall energy consumption will be at the leading level in the industry. The comprehensive energy consumption for oil refining in this project is lower than the energy consumption requirements set for new enterprises in the oil refining sector, and its energy consumption per unit of output is also at the leading level in the industry.

Waste heat recovery holds great potential and is definitely a trend.