Biorefining is a rapidly evolving segment that utilizes a variety of feedstocks and processes to create bioproducts (energy, materials, and chemicals). Unlike conventional chemical and oil & gas processes that have developed standard approaches over time, each biorefinery may have its own unique and proprietary manufacturing process to transform feedstock(s) into finished products.
By David Bisson, Market Development and Projects Lead – Armour Valve, and Stephan Eckhardt, CEO – SchuF USA
Bespoke processes often call for custom valve solutions that require careful evaluation and selection; especially for valves that are critical to plant performance and application reliability. It is therefore crucial to involve trusted and experienced valve suppliers at the onset of the engineering process.
The best time to engage with a valve supplier is as early as the small-scale pilot plant stage; at this stage decisions that will impact the full-scale plant are made. Partnering with the right supplier early on will help operators prepare to scale up to commercial plant size.
From Feedstocks to Circular Products
Biorefining feedstocks can be varied and include by-products from conventional industries such as forestry, pulp and paper, agriculture, aquaculture, industrial and other solid waste. Bioproducts are typically divided into three categories: bioenergy (including ethanol, biogas and syngas), biomaterials (including bioplastics, biorubber, and biocomposites), and biochemicals (including basic and specialty chemicals, pharmaceuticals, and biocosmetics).
To select the right valve for an application, the inherent properties of a feedstock, such as abrasiveness, corrosiveness, viscidity/viscosity, and flammability must be considered during the design phase of the project. Working with valve suppliers that can offer customizable features suited to specific applications will result in the delivery of the performance and longevity that each plant seeks for its investment.
Valve Selection Criteria
Several features should be considered during engineering and selection.
Dead Space
Dead space can cause cross contamination from batch to batch that should be avoided and is one of the leading causes of valve failure when working with feedstocks that can solidify or build up over time. Selecting valves that minimize or eliminate dead space – ram and disc valves – increases run time and reduces maintenance costs.
Ram valves provide a ram that either protrudes into the process flow or remains flush with the vessel or pipeline so that no build-up can occur. Disc valves serve the same purpose but use a disc instead of a ram to control the process flow whether it is lowering from a vessel or pipeline or pushing into the media flow. This occurs as the feedstock and processes involve heat and pressure.
Material Selection
As in all applications, proper valve material selection is crucial. Using an inferior material can lead to premature valve failure, leakage, and system downtime, which may result in costly repairs and production losses. High-pressure and temperature biorefining applications require valves to be comprised of specialized materials such as high alloy steel or titanium.
A knowledgeable valve supplier can serve as a trusted advisor to help spot potential pitfalls and identify best-fi t materials for the application early in the engineering process. This will help to ensure the valve’s longevity, reliability, and optimal performance as well as compliance with industry regulations and standards.
Process Simulation and Modeling
As technology differs from plant-to-plant in biorefining, partnering with a supplier that is able to model the process data to design a custom solution, is in an operator’s best interest. If a process is new and unique, many do not want to be a test case for an unproven technology.
For example, when looking at a control valve, the choice depends on factors such as the desired output and whether it is regulating pressure, flow, or generating flashing within a vessel. Not all suppliers offer process modeling that demonstrates how the valve should perform under different operating conditions. Collaborating with a supplier that can provide these services can help optimize each valve’s performance in the field, minimizing the risk of potentially expensive and extensive on-site adjustments.
Isolation Points
The incorporation of isolation points for a successful system design allows maintenance teams to service equipment and control valves safely and effectively. Engineered or customized solutions provide the best means to isolate and drain a line for maintenance purposes, especially when challenging media are involved.
Double block and bleed valves are critical equipment that play a vital role in safely isolating and draining a system. Line blinds are also an effective method of providing positive shut-off for lines that can be opened to the atmosphere. This eliminates the need to unbolt an isolation point, spread flanges, insert a paddle blank, and then re-bolt the flanges.
Instead, a line blind enables the unloading of the clamping force by way of a hand wheel, allowing for the switching of the spectacle plate, before re-engaging the clamping force, to isolate the line. Additionally, the line blinds reduce stress on welds and piping systems since they do not require the spreading of flanges and piping. Compared to standard paddle blanks, line blinds eliminate the need for special tools, are safe for single person operation, and reduce the time required to isolate a system and once again make it operational.
Serviceability
With customized valve solutions, serviceability is a critical concept to consider in the design plan. It is essential to ensure that a chosen valve supplier can not only offer parts and service, but also technical support. Local support can be advantageous when it comes to servicing, troubleshooting, and determining the best course of action for service or repairs. Having a local team to turn to when problems arise not only provides peace of mind but may also reduce downtime and play a vital role in keeping plants operational.
Conclusion
Biorefining is constantly evolving as new ways to use biological, renewable feedstocks to produce energy, materials, and chemicals are developed and requires customized solutions to meet unique process requirements. Careful evaluation and selection of critical valves integral to plant performance and application reliability are crucial for successful operations. With the right expertise and support, bespoke valve solutions help ensure the safe, efficient, and reliable operation of refining processes.
Engaging valve suppliers in the early stages of the engineering or project process ensures the appropriate valves and technologies are applied to achieve optimal performance outcomes. This approach can help minimize downtime, reduce maintenance costs, and increase plant output. By collaborating closely with valve suppliers from the outset, engineers can design and select the best-suited valves and technologies for the specific application requirements, leading to more efficient and reliable operation, better performance outcomes, and ultimately contributing to the overall success of the project.
