DME production from natural gas

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Di-methyl-ether (DME) is mainly used as a propellant and can also be used as a substitute for diesel
fuel in diesel engines with the advantage of high efficiency and low exhaust emissions (no
particulates, no Sulphur, and low NOx). It is an alternative to liquefied petroleum gas (LPG).
DME is usually produced directly from natural gas. It involves three main steps: 1) converting
natural gas into synthesis gas (mainly CO2, CO and H2), 2) methanol synthesis and 3) DME production
and separation. You are required to simulate this process.
Converting natural gas into synthesis gas
In this step, methane is first reacted with steam to produce syn-gas in a conversion reactor R-ref at
temperature TR-ref and pressure PR-ref. This steam reforming is an isothermal process, so appropriate
heating or cooling is needed.
𝐶𝐶𝐶𝐶4 + 2𝐶𝐶2𝑂𝑂 → 𝐶𝐶𝑂𝑂2 + 4𝐶𝐶2 (R1)
𝐶𝐶𝐶𝐶4 + 𝐶𝐶2𝑂𝑂 → 𝐶𝐶𝑂𝑂 + 3𝐶𝐶2 (R2)
The conversion rate for each reaction is given in your individual design specification. The gas product
from R-ref is fed into a component splitter (CS-100) where CO and H2 at the molar ratio of 1:2 leave
the splitter from the top as Stream CS100-top while the rest of the product leaves from the bottom
as Stream CS100-bottom.
Methanol synthesis
Stream CS100-top is cooled down to TR3 (the temperature of 1st methanol synthesis reactor) before
the below equilibrium reaction takes place in the reactor.
𝐶𝐶𝑂𝑂 + 2𝐶𝐶2 = 𝐶𝐶𝐶𝐶3𝑂𝑂𝐶𝐶 (R3)
This reaction can be found in HYSYS equilibrium reaction library. The gas stream from this reactor
goes to a component splitter where methanol is separated as Stream Methanol 1 and sent to DME
production section while the unreacted gas is recycled back to the reactor.
Stream CS100-bottom is cooled down to TR4 before it enters a CSTR reactor where CO2 is converted
into CH3OH at the temperature of TR4.
𝐶𝐶𝑂𝑂2 + 3𝐶𝐶2 = 𝐶𝐶𝐶𝐶3𝑂𝑂𝐶𝐶 + 𝐶𝐶2𝑂𝑂 (R4)
You are required to use a kinetic model to simulate this reaction. The forward reaction rate constant
kF and backward reaction rate constant kB are given below:
𝑘𝑘𝐹𝐹 = 1.04 × 1022𝑒𝑒�
−170000
𝑅𝑅𝑅𝑅 �

Sample Solution

Dimethyl Ether (DME) is a safe and cost-effective alternative fuel made from natural gas. DME has qualities that are extremely comparable to LPG. DME is a clean and easy-to-handle fuel that may be utilized in a variety of applications, including power generation, transportation, home heating and cooking, and so on. A novel method for producing DME directly from synthesis gas has been devised. The project to build a 5 ton per day DME production pilot plant (5TPD) was completed successfully in FY2001, and the project to build a 100 ton per day DME production demonstration plant (100TPD) began in FY2002. The Ministry of Economy, Trade, and Industry is supporting and funding these projects (METI). JFE Direct DME Synthesis will pave the path for more cost-effective DME mass production.

earle’s famous “Chinese Room” argument that was discussed in Chapter 2 of How the Mind Works, was one of the most interesting arguments to display claims of artificial intelligence. Basically the claim as that computers can and will at least try to master the act of thinking. The argument was based upon how Searle sees himself in a room alone and is trying to follow and get on board with a computer that is that is responding to Chinese characters. However, Searle knows he is not able to grasp or understand any of it, yet he attempts to manipulate numbers and a variety of symbols in order to trick those outside of the room. His manipulation of such numbers and symbols, produces Chinese characters, which allows him to convince those outside the room that there is someone who can actually speak Chinese inside the room. Searle believes that though the computer appears to understand what is going on, in all reality it actually doesn’t understand it. It can be concluded that purpose of this argument was the refute the point that a computer can function on its own. Searle believes that if a man cannot understand Chinese even when he was manipulating numbers and symbols, then neither can computers. A computer is no human and can never be like one.

Pinker’s response to the “Chinese room” argument is reluctant. He says that Searle has stated nothing to do with something that can be scientifically valuable. And that Searle is merely stating about the word “understand”. In fact, it is talked about in abroad way, which isn’t too clear or concise. Pinker says that humans are filled with meat, while computers are filled with information. Humans need the right buttons to be pushed before he/she can accurately process information. Similarly, computers need the right information when processing in search for other information. Both need some sort of push in order to be successful and without that push humans and computers both cannot function and “understand”. Pinker feels that we can be just as unreliable as computers can be.

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