Carbon Emissions Of Modern Coal Chemical Industry And The Impacts On Economy

Coal chemical industry can be divided into traditional industry and modern industry,the traditional industry including coking,ammonia synthesis,calcium carbide,methanol,et al,and the traditional industry has a long history and matures;modern industry is of advanced technology,complex process,oil substitute,almost commercialized in recent years,mainly including coal to synthetic natural gas?CTSNG?,direct coal liquefaction?DCL?,indirect coal liquefaction?IndCL?,coal-based methanol to olefin?CTMTO?,coal-based methanol to propylene?CTMTP?,and coal to ethylene glycol?CTEG?et al.The energy consumption of modern coal chemicals is high in production process,and large scale construction engineering is developed.Carbon accounting is confined to process emission?direct emission?and indirect emission induced by electric and steam in existing research.?Depreciation? has been induced in this paper to study the carbon emission produced by the large equipment and devices in the carbon emission lists of modern coal chemical industry,in order to reflect the carbon footprint full view of modern chemical products exactly,and analyse the carbon emission source deeply.The result shows that: in coal mining the CO₂ emission is 0.098t/t coal directly,indirect emission induced by electric and steam is 0.027t/t coal,emission induced by depreciation of equipment is 0.003t/t coal;in direct coal liquefaction,direct emission is 5.8t/t oil produced,indirect emission induced by electric and steam is-0.14t/t oil,emission induced by depreciation is 0.08t/t oil.It shows that emission induced by depreciation is 1.4-2.4% of the sum of direct emission and indirect emission induced by electric and steam.In the comparison of coal chemical process,energy efficiency and carbon emission per unit heat value has been investigated to evaluate the carbon emission level of modern coal chemical industry,but it is not reasonable to non-fuel processes including CTMTO,CTEG,et al.The CO₂ emission per unit output value and per unit industrial added value has been proposed to be supplementary index in this paper.In the index system,the technology level and developing situation of CTSNG,coal to methanol,coal to dimethyl ether,DCL,IndCL,CTMTO,CTMTP,CTEG has been analysed,the energy conversion efficiency,carbon emission per unit product,carbon emission per unit heat value,carbon emission per unit output value,and carbon emission per unit industrial added value have been compared systematically.The results show that,although CO₂ emission per ton product of coal-based methanol and DME are 3.56 t and 5.0t respectively,quite low;but CO₂ emission per unit heat value is quite high,0.159t/GJ and 0.160t/GJ respectively.In the oil price system of $80 per barrel,compared with national average level,CO₂ emission per 10000 yuan GDP is 5.0-6.5 times of that,CO₂ emission per 10000 yuan industrial added value is 2.8-3.7 times of that to modern coal chemical industry except CTSNG and coal to methanol;CO₂ emission per 10000 yuan GDP of CTSNG and coal to methanol is 11 and 9 times of that respectively,CO₂ emission per 10000 yuan industrial added value is 7.4 and 5.2 times of that respectively.In the oil price system of $40 per barrel,compared with national average level,CO₂ emission per 10000 yuan GDP is 6.5-10.3 times of that,CO₂ emission per 10000 yuan industrial added value is 3.6-5.9 times of that to modern coal chemical industry except CTSNG and coal to methanol;CO₂ emission per 10000 yuan GDP of CTSNG and coal to methanol is 15.7 and 12.6 times of that respectively,CO₂ emission per 10000 yuan industrial added value is 10.4 and 7.2 times of that respectively.Economic efficiency is internal driving force to coal chemical industry,and it is important to study carbon emission to economic influence for future developing trends.In the future,carbon tax maybe the important factor to reduce coal chemical industry profit,on the basis of different coal chemical product cost and carbon emission,the influence on different coal chemical industry product tax cost of carbon tax rate has been analysed.The sequence of sensitivity coefficient is that: CTSNG> coal to methanol> coal to DME> CTMTO> CTEG> DCL> IndCL,it shows that CTSNG is most sensitive,chemicals secondly,coal to liquid last.In fact,many factors affect the techno-economic efficiency besides carbon tax,in the past techno-economic analysis mainly relied on techno-economic definition of variables to find its correlation,which the data quality is high,computing process is complex,and it is unable to analyse the influence on economic efficiency when many factors change at the same time.A new techno-economic analysis method is proposed and established in this paper.In the method,a serial of specific conditions has been experimentally designed in the fluctuation range of many variables,economic index is calculated in specific conditions by mature techno-economic analysis software;and then target index and main variables are correlated statistically,the simple equation sets which can reflect techno-economic efficiency has been formatted;in the end,sensitivity and uncertainty will be analysed on the basis of the equation sets.Results show that,operation relations from the method is simple,suitable range is wide,analysis results is scientific and suitable,and the analysis period is greatly shortened,and manpower and financial resources has been saved.There are four steps in the new techno-economic analysis method,ensure study boundary and definite target indexes,determine key influence factor and level,experimental design and data calculation,model selection and verification.JMP software is used in model fitting and selection in this study.To be simple,practical,suitable,in the model establishment and selection,principles are followed as bellows:Principle?1?: Simple first and complex second.Influence factor and target index are fitted in the serial of linear term,cross term,quadratic term expression,if the linear term can fit the predict need,the cross term and quadratic term will not be added.Principle?2?: Test results significance.To limit the interference of ?irrelevant? term,the non-significant term should be eliminated,the higher p-value term should be rejected first in hypothesis test in the study.In the process of model fitting,the term of p?0.1 is retained,and the term of p>0.1 is eliminated considered.Principle?3?: Link practice.The multivariate multiple expressions fitted by software are wholly acquired on the basis of mathematical statistics,the practice will not be ?considered?.So,the term not meet the practical significance will be eliminated.Principle?4?: R² acceptable.Residual squared?R²?is an important index to determine the model rationality,R² is in the range of 0-1,when R² is closer to 1,and the equation related is more fitting to experimental data,and the reference is higher.The R²?0.95 of the forecast equation is required in the model establishment.By using CTSNG,DCL,IndCL,CTMTO,CTMTP,and CTEG as examples,the influence of uncertainty of product price,coal price,construction investment and carbon tax rate are analysed on internal rate of return after tax,return on investment after tax?including construction period?,financial net present value of project investment income,after tax profit,CO₂ emission per unit profit?after tax?.Monte Carlo simulation analysis result shows that: in the downturn market,the price of polyolefin is 6000-8000 yuan,CTMTO is profitable if the coal price is 100-300 yuan/t;in normal market: the price of polyolefin is 8000-10000 yuan,the coal price is 200-400 yuan/t,and carbon tax rate is 20-60 yuan/t,confidence interval is 15.69%-15.77% when the CTMTO internal rate of return is in 95% level;in the overheated market,the coal price is 500-700 yuan/t,when the price of polyolefin is 8000-10000 yuan,CTMTO is of poor earnings,the confidence interval is 11.60%-11.68% when the internal rate of return is in 95% level.On the basis of six kinds of coal chemical industry techno-economic analysis model,the general model of modern coal chemical industry techno-economic analysis is established to meet different needs.Analysis shows that,in downturn market,the economics of CTMTO is a little higher than CTMTP;in overheated market,the economics of each modern coal chemical industry is properly well,but if the price of coal is higher,up to 500-700 yuan/t,the economic efficiency decreases sharply.Using the new method in this paper,techno-economics base on CCS,CCUS of modern coal chemical projects has further been analyzed,the product price,coal price,carbon tax rate,high concentration CO₂ storage quality,high concentration CO₂ storage cost,high concentration CO₂ utilization,high concentration CO₂ utilized income effect on technic economics of CTMTO has been studied specifically.By sensitivity analysis,most sensitive effect factors are polyolefin price,high concentration CO₂ utilization,and coal price to internal rate of return,payback period,and net present value and after tax profit;sensitivity coefficient of polyolefin price is about 0.68-0.795,sensitivity coefficient of high concentration CO₂ utilization is about 0.09-0.139,and sensitivity coefficient of coal price is about 0.083-0.101.To CO₂ emission per unit output value,the most significant effect factor is high concentration CO₂ utilization,sensitivity coefficient is 0.528,the second is high concentration CO₂ storage quality,sensitivity coefficient is 0.38,and the third is price of polyolefin,the sensitivity coefficient is 0.133.