工藝說明
Process description
本回收裝置由緩沖罐、壓縮、干燥、制冷、貯罐等單元組成，用于回收化肥沼氣等廠過程中產(chǎn)生的二氧化碳，并將其純化以供使用。
The recovery unit is composed of buffer tank, compression, drying, refrigeration, storage tank and other units. It is used to recover carbon dioxide generated in the process of fertilizer and biogas plants and purify it for use.
緩沖
buffer
沼氣回收甲烷生產(chǎn)過程排出的二氧化碳氣體先經(jīng)緩沖罐穩(wěn)定氣體壓力，同時也起到分離作用。然后二氧化碳氣體借助于二氧化碳氣體壓力經(jīng)干燥塔凈化，達到脫水目的。
The carbon dioxide gas discharged during the methane production process of biogas recovery is stabilized through the buffer tank, and also plays a separation role. Then carbon dioxide gas is purified by drying tower with the help of carbon dioxide gas pressure to achieve dehydration.
干燥與過濾
Drying and filtering
經(jīng)凈化后的二氧化碳進干燥器，二氧化碳從上部進入分子篩床，二氧化碳經(jīng)分子篩床層吸附脫除其中的水分；干燥器為切換操作，即當一臺處于8小時的吸附狀態(tài)時，另一臺則處于再生冷吹狀態(tài)，再生氣為低壓殘氣，來自后續(xù)工段的低壓常溫殘氣經(jīng)電加熱器加熱后，從再生床的下部通過分子篩床層，加熱脫除分子篩中被吸附的水分雜質(zhì)，經(jīng)再生，以備再次轉入到吸附狀態(tài)。
The purified carbon dioxide enters the dryer, the carbon dioxide enters the molecular sieve bed from the upper part, and the carbon dioxide is absorbed by the molecular sieve bed to remove the water therein; The dryer is in switching operation, that is, when one is in the 8-hour adsorption state, the other is in the regeneration cold blowing state, and the regeneration gas is the low-pressure residual gas. The low-pressure normal temperature residual gas from the subsequent sections is heated by the electric heater, and then heated from the lower part of the regeneration bed through the molecular sieve bed layer to remove the adsorbed moisture impurities in the molecular sieve, which is regenerated for the purpose of being transferred to the adsorption state again.
壓縮與冷卻過程
Compression and cooling process
來自的二氧化碳氣體，進入壓縮機(帶有中間冷卻及末級冷卻)，二氧化碳經(jīng)三段壓縮冷卻后，在壓力2.5MPa，常溫狀態(tài)下去下游繼續(xù)加工處理。
The carbon dioxide gas from the compressor (with intermediate cooling and final cooling) enters the downstream for further processing at a pressure of 2.5MPa and normal temperature after being compressed and cooled in three stages.
分離與除雜質(zhì)
Separation and impurity removal
自壓縮機來的二氧化碳經(jīng)冷卻、再次分離游離水，二氧化碳去凈化床，其中可吸附的雜質(zhì)被除去，二氧化碳從床層上部排出去干燥器。
The carbon dioxide from the compressor is cooled and the free water is separated again. The carbon dioxide goes to the purification bed, where the adsorbable impurities are removed. The carbon dioxide is discharged from the upper part of the bed to the dryer.
冷卻與精餾過程
Cooling and distillation process
經(jīng)前述凈化處理的原料氣進冷卻器的管內(nèi)，在此原料氣被管外來自殘氣總管的低壓殘氣冷卻之后在液化器中被管外蒸發(fā)的R717繼續(xù)冷卻冷凝，進二氧化碳精餾塔，在塔內(nèi)利用精餾的方法脫除原料氣流中的不凝氣體等雜質(zhì)，在再沸器得到液體二氧化碳產(chǎn)品，產(chǎn)品再經(jīng)節(jié)流至1.7MPa，溫度約-25℃去原裝置產(chǎn)品貯罐，塔釜的熱源為來自冷凍系統(tǒng)冷凝器上部抽取的氣體，為塔頂回流冷凝器提供冷源的是節(jié)流后的液體氨，控制塔底二氧化碳含量達到工業(yè)級為前提，未被冷凝的，含不凝氣雜質(zhì)的氣體則從冷凝器頂排出，并經(jīng)壓力調(diào)節(jié)閥節(jié)流為低溫殘氣去冷卻器回收冷量。
The purified feed gas goes into the pipe of the cooler, where the feed gas is cooled by the low-pressure residual gas from the residual gas header outside the pipe, and then continues to be cooled and condensed by the R717 vaporized outside the pipe in the liquefier. The feed gas goes into the carbon dioxide rectifying tower, where the non condensable gas and other impurities in the feed gas flow are removed by rectification. The liquid carbon dioxide product is obtained in the reboiler, and the product is throttled to 1.7MPa, The temperature is about - 25 ℃ to the original product storage tank. The heat source of the tower bottom is the gas extracted from the upper part of the condenser of the refrigeration system. The liquid ammonia after throttling is used to provide the cold source for the tower top reflux condenser. On the premise that the carbon dioxide content at the bottom of the tower reaches the industrial level, the gas that is not condensed and contains non condensable gas impurities is discharged from the top of the condenser, and is throttled by the pressure regulating valve to the low temperature residual gas to the cooler to recover the cold energy.
產(chǎn)品貯存
Product storage
來自再沸器塔釜的液體二氧化碳經(jīng)液位調(diào)節(jié)閥減壓至壓力1.7MPa，溫度約-25℃后去二氧化碳貯罐，由于來自再沸器的液體經(jīng)節(jié)流后必然產(chǎn)生少量氣體，這部分氣體連同在貯存過程產(chǎn)生的蒸發(fā)汽體一并從罐頂上部的出口管排出，并經(jīng)壓力調(diào)節(jié)閥減壓成低溫殘氣去殘氣總管，在冷卻器中回收冷量。
The liquid carbon dioxide from the tower bottom of the reboiler is depressurized to a pressure of 1.7MPa through the liquid level regulating valve, and then goes to the carbon dioxide storage tank after the temperature is about - 25 ℃. Since the liquid from the reboiler will inevitably produce a small amount of gas after throttling, this part of gas, together with the evaporation vapor generated during the storage process, will be discharged from the outlet pipe at the top of the tank, and reduced to low temperature residual gas through the pressure regulating valve to the residual gas header, where the cold energy will be recovered in the cooler.
The above is a detailed introduction to biogas purification, and we hope it will be helpful to you. If you have any questions, please contact us. We will provide services for you with our attitude http://www.shdhtech.com
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2022-12-27
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