School of Engineering Engineering

Designs and Innovation Subject

Code: ENG 2523

Design Proposal of{Novel Adsorbent for Carbon Capture (Mechanical Section)}

Project SupervisorDr. Padmesh and Dr. Rebecca

Shaun Yu Yong Jian 0308959

Content Page

Abstract

The team project is to device a filter housing that will support the filter which is to be used to absorb the carbon from the carbon dioxide that vehicle produces The concept behind the carbon filter revolves around the principle of a simple air filter. The design of the carbon filter consists of three channels, the main channel which houses the detachable carbon adsorbent, a bypass channel and a residue channel. These three components will attribute to the efficient removal of carbon gases from the car’s exhaust. The carbon filter will be installed in a vehicle’s exhaust system, just after the catalytic converter. The targeted life span of the filter is half a year.

IntroductionCarbon dioxide (CO2) is a natural gas that allows sunlight to reach the Earth but also prevents some of the sun's heat from radiating back into space, thus warming the planet. Scientists call this the greenhouse effect. The team project is to device a filter housing that will support the filter which is to be used to absorb the carbon from the carbon dioxide that vehicle produces. This device that filters the carbon dioxide will attach to the exhaust of the vehicle using the assembly the team is designing hence that the processes of filtering will optimized. This project focuses one of 14 engineering grand challenges, which is developing carbon sequestration methods. Currently scientists are working on a way to capture carbon dioxide that has been release to combat global warming. One of the best ways is to stop it at the source before it reaches the atmosphere. Power plants and transportation vehicles, which burn fossil fuels, release huge amount CO2 into the air. This will further resulted in a high rate of CO2 in the atmosphere. The technology that the team is trying to innovate is quite new especially in the automotive industry which produce the highest CO2 annually. Though currently in most of the petroleum industries carbon capture is being implemented, in the automotive industry is still new to the idea and slow in the application of carbon capturing into their exhaust system. The team design will be simple, easy installation, stress-free maintenance as the filter could be replace, and leaving room for further upgrade for future development. Safety feature such as a bypass pressure valve will be integrated into the design as exhaust flow in the exhaust system could affect the vehicle performance and any blockage could damage the engine, leaking could occur that can be lethal

Design Solution

2.2 Main channel (filter)The function of the main channel (Part 2 in Figure 6) is for efficient filtering of

carbon gases in the exhaust. The main channel will be approximately 11 cm in diameter, and consists of a detachable housing for the carbon absorbent. The metal housing is positioned at an angle, approximately 60˚, and is detachable by means of a sliding mechanism and a latch. The concept behind the bigger diameter and the tilting of the filter is to increase the surface area of adsorption by the filter. The bigger the diameter, the more gas is allowed to enter the main channel. By tilting the filter, the surface area increases to allow more carbon gases to be adsorbed. Pairing the large channel and the increased surface area of the filter, carbon gases will be effectively and efficiently adsorbed by the filtration system, thus emitting cleaner emissions to the environment.

2.3 Bypass channelThe function of the bypass channel (Part 1 in figure 6) is to allow and outlet for

the air in case there is a build-up in pressure due to the carbon filter being clogged. The build-up in pressure if left unattended could potentially damage the efficiency of the engine as well the internal integrity of its components and ultimately be hazardous for the driver. To overcome the issue, a simple pressure sensitive device would be placed at one entrance of the bypass opening which would only open if the pressure reaches a certain limit of ……. Unfiltered gases to bypass the filter and ultimately lowering the overall pressure within that section. The reason why we didn’t choose to just leave the bypass channel open is to maximize the absorption of carbon dioxide gases in the filter and to prevent unfiltered from easily escaping through the bypass.

Design changes were made towards the pressure valve that was to be placed at the entrance of the bypass channel. The initial concept design of the pressure valve utilizes a diaphragm which would move and stretch depending of the pressure of either side of the bypass channel and main channel which houses the filter. The movement of the diaphragm would then push and the spring which would then cause an opening for gas to pass. However, the issues that arose was that the typical diaphragm needed would not last in s high temperature environment and the sensitivity to pressure was difficult to control. To solve these issues, we chose a much simpler approach which was based on a spring mechanism similarly found in mouse traps. This method proved easier to build, as the only modifications required were to adjust the strength of the spring by reducing the number of coils as well as welding a cap which seals the entrance to the bypass channel on to the device.

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Figure 7: Pressure valve concept [1]

The spring pressure and the exhaust pressure act against each other and whichever is greater would determine the position of the needle and the opening of the orifice of the valve. [1] Our team is also planning to maybe installing an electrical switch at the valve, such that when the valve opens, the switch is closed and it activates a buzzer in the car dashboard, indicating the need to replace the carbon filter.

2.4 Residue channelThe residue channel (Part 3 in figure 6) is mainly a compartment in which the residue

is collected and discarded. The concept of the residue channel is to prolong the efficiency of the carbon filter. When the car is stationary and the engine is off, there is no airflow in the exhaust pipe. Thus some of the residue collected on the filter can fall into the residue channel via an opening, and settle down. This helps to remove some of the carbon adsorbed by the filter in solid form and thus prolonging the filter’s efficiency. The residue channel is also the opening of the device, where it enables the servicemen to detach the filter and replace it with a new one.

Materials

The material required to build the carbon filter is stainless steel. The reason behind this is because of its high melting point (1425-1540˚C) and durability. [3] The temperature in warmed-up gasoline engines can vary from 300°C to 400°C during idle, rising even up to about 1000°C, depending on the driving conditions; therefore the high melting point of steel justifies its use in building the carbon filter. Furthermore, stainless steel is a standard

material used for automotive components [4]

Typical gasoline engine exhausts have maximum back pressures of 4”Hg. [2] a chart specifying a range of engine models and their exhaust flow rates can be found in Appendix A of this report. Due to the high flow rate of the exhaust, the proposed material used is mild steel which can withstand high amounts of pressure and is typically used in the manufacturing of catalytic converters, another filter present in most commercial cars today.

use mild steel as the base prototyping material.As of this phase we have a sufficient amount of information and data for the final product therefore for the second phase we use a more rigid and harder material to construct the prototype. The reason behind the second construction of the prototype is toanalysed/study the inner working principal of the mechanism. Besides that, the cost of mild steel is cheap and can be easily shaped; a plasma cutter or automatic hand saw can also be used to cut the metal sheets. In order to assemble it a welding tool can be used to join the pieces together. Therefore this is an inexpensive method to prototype our product before manufacturing the final product.